The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 05, 1988
Filed:
Jun. 27, 1986
Applicant:
Inventors:
Robert P Foss, Hockessin, DE (US);
Daniel R Fruge, Wilmington, DE (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03C / ;
U.S. Cl.
CPC ...
430264 ; 430265 ; 430266 ; 430267 ; 430268 ; 430569 ; 430630 ; 430545 ; 430627 ; 430628 ; 430941 ;
Abstract
Sharper edges are obtained in silver halide wash-off films for tanning development when from 5 to 60% of the unhardened gelatin binder in one or more layers is replaced with a synthetic amphoteric polymer consisting essentially of at least one of each of three constituents: (a) carboxylic acid, (b) alkyl primary amine, and (c) secondary and/or tertiary amine, the amphoteric polymer having an isoelectric point of from 4 to 8.